Albert c



A. C.4 DIEFFENBAGH.

REAR SIGHT FOR SMALL ARMS.

(No Model.)

Patented Jan. 2 2, 1895.

` FDL-1f.- El; Swwwbw 4o from the left of the said ligure.

45 is held at the desired elevation.

UNITED STATES PATENT OFFICE.

ALBERT C. DIEFFENBACH, OF THE UNITED STATES NAVY.

REAR SIGHT FOR SMALL-ARMS.

SPECIFICATION forming part of Letters Patent No. 583,003, dated January22, 1895.

Application filed June 12, 1894:. Serial No. 514,313. (No model.)

To all whom it may concern.-

Be it known that I, ALBERT C. DIEEFEN- BACH, an ensign in the UnitedStates Navy, and a citizen of the United States, stationed at 5Hartford, in the county of Hartford and State of Connecticut, haveinvented certain new and useful Improvements in Sights for Riiies orother Small-Arms and I do hereby declare the following to be a full,clear, and exact de- Io scription of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in sights for rifles or other smallarms, and it I5 consists essentially in providing a simplified 2o of therifie, and provided with a notch-arc which arc is adapted to be set atany desired elevation, and to be normally contained within the wood workof th'e stock. The sight is also provided with an improved form ofsightl z5 notch, and with a marked line adapted to assist the eye inrapidly adjusting itself to the line of sight. These and the variousother features of the herein described invention will be more clearlyunderstood by reference to 3o the accompanying drawings, in which theame parts are indicated by the same letters Figure l represents aperspective view of my improved rear sight as mounted on a rifle,

3 5 and as set for one thousand yards. Fig. 2 represents a sideelevation of the sight and its base as detached from the gun and set forfifteen hundred yards. Fig. 3 represents a front view of the deviceshown in Fig. 2, or as seen Fig. 4 represents a section along the line x@cof Figs. 2 and 3, and looking down. Fig. 5 represents a perspectiveview of the sliding block and pawl carried thereby, by means of whichthe sight Fig. 6 represents a section similar to that shown in Fig. 4with a slightly modified means of holding the pawl against the notchedarc. Fig. 7 represents a perspective view of the sliding block 5o andpawl used in the modification shown in Fig. 6. Fig. 8 represents a sideelevation of another modification for operating the pawl,

`of sight.

andFig. 9 represents a section along the line y y of Fig. 8, and lookingto the right. Fig. 10 represents a rear view of the sight notch andthefront sight when the eye is in the proper position. view to that shownin Fig. l0, when the eye is to the left of the line of sight, and Fig.l2 represents a similar view to that shown in Fig. 10 when the eye is tothe right of the line of sight.

A represents the riiie barrel which is partly inclosed in the ordinarywood cover A', and

`the forward portion B of the stock. This wooden cover A is cut away asat a and the stock is cut away to allow the bracket D4 carrying thenotched arc d5 to swing freely thereinto.

The rear-sight D is pivoted as at e to the base or frame C which issecured to the barrel by means ofa screw passing through the hole c, or

byva plurality of screws passing through suit.

able holes, or is soldered to the gun or otherwise rigidly attachedthereto in any convenient way.

The rear sight D is provided with a solid flat leaf D', which is knurledor otherwise darkened along the upper face as at d3 leaving a lightstreak D2 between the said knurlings, and in the same vertical planewith the line The forward end of this leaf terminates in a roundedportion D3 in which the sight notch D0 is cut. This sight notch D0 isprovided with a cylindrical bottom cl2 and vertical, o r nearly Verticalsides d extending up to the edges d? and then flaring outward in theconical surfaces d. This peculiar shape of sight notch enables the samenotch to be used for all elevations, and renders it possible to readilyget the eye iii the prope/r line of sight, and to make adjustment for"elevation for shorter distances than the point-blank range as will behereinafter more fully described. The edges of the'rounded portion D3 ofthe head of the sight are knurled as at d4 for convenience in graspingthe sight and raising the same to the proper adjustment.

The leaf D is provided with a downwardly projecting bracket D4 whichcarries at its forward end a notched arc d5. This arc is provided withnotches corresponding to given ranges or increments of range, whichnotches start at the point-blank range and continue Fig. ll represent-sa similar IOO up to the maximum range, upon which the small arm of themarksman may be relied for efficient service.

For ordinary naval or military purposes, I preferably adjust the sightso that all under five hundred yards shall be point-blank range, andabove this a notch is provided for each one-hundred yards of additionalrange up to two thousand yards which is as far as the arm of themarksman can be depended upon.

A springoperated pawl engages at the various notches as will behereinafter more fully described.

In order that there may be less tendency of the pawl to slip over two,or three, or more, of the upper and finer notches, I preferably have thenotched arc cutin toward the upper end, and make each of the uppernotches project a little beyond the notch above. In this way if the pawlis moved back far enough to slip over one notch it will be more likelyto catch on the tooth below, and so the pawl is more likely to catch oneach tooth as the sight is elevated. This-is of especial importance in.firing at night, when each click of the pawl will indicate anadditional hundred yards of elevation.

For use with the herein described sight any convenient form of pawl maybe adopted and I have shown several forms in the drawings, any one ofwhich might be used, but preferablythat shown in Figs. l to 5. In thesefigures the base C, which should preferably be cut away as at c tolighten the same, is provided with a solid portion c2 into which thescrewthreaded end h of the bolt H engages. This base C is also providedwith a cylindrical groove c3 into which the hollow sleeve F slides. Thissleeve F is rigidlyattached to the pawl F2 andthe block F, which blockis provided with an arrowfand an index edge f which indicate the eevation on the notched arc. The pawl is olrdinarily held in engagementby means of the spring K which is held between a shoulder at the bottomof the sleeve F', and the shoulder 7L near the head of the screw I-I.

In the modification shown in Figs. 6 and 7, the screw I-I engages in thenut F4 carried by the block F, which nut is screw-threaded as at f4,shown in Fig. 7, the spring K being held between the head of the saidbolt H, and the shoulder c5 at the end of the cylindrical groove c4 inthe base G. In this form of device the bolt H and the block F movetogether, and the spring K normally holds the pawl F2 in engagement withthe notched arc These sliding blocks carrying the pawls should beknurled or otherwise roughened as at f2 for convenience of manipulation.

In the form of device shown in Figs. 8 and 9 a sliding block F(i ispivotally connected to the pawl F5, which pawl is normally pressedforward by the spring f 6 shown in dotted lines in Fig. 8. The pawl F5is pivoted on the screw f5 set in the base C. The block F6 should beprovided with the arrow f and index edge f', and should be roughened asalready described with reference to the block F, but thesefeatures havebeen omitted from the drawings for the sake of clearness therein.

S, shown only in Figs. 10 to 12, represents the front sight, and when inthe proper position, the point of the vsaid front sight should be in thevertical plane passing through a center ofthe rear sight notch D0.

The relative positions of the sides of the front sight with the annularedges do will enable the marksman to rapidly get the eye in the line ofsight. It will be seen that, with a little practice, variations in thespeed of the object aimed at may be readily compensated for; and thatalso by slightvariations in the height that the point of the front sightextends above the annular edges do. Adjustments for' sighting withinpointblank range, or between any of the ranges indicated on the notchedarc may be made. These adjustments are a matter of practice and willdepend upon the skill of the marksman.

In order to use the sight, it should be left down or in the initialposition for all ranges less than the point-blank range indicated on thenotched arc, and any adjustments inside of this range should be made bythe eye of' the marksman. To set the sight, say at a thousand yards, theleaf D is swung upward about its. pivot e, until the pawl has clickedtive times, or until the arrow or index edge points to ten.

To lower the sight, draw back the block F, and ease the leaf D down tothe initial position.

Since the pawl will click as it passes over each tooth on the notchedarc, the herein described sight is eminently adapted for use at night,or when the marksman desires to keep his eye on the target whileadjusting the sight.

the sliding block and allows the sight to fall into the initialposition, that for point-blank range. This is done to make sure that thesight has notbeen set at any elevation. Then if the marksman raises thesight slowly until the pawl has clicked five times he will be sure thatthe sight is set at the right elevation.

In order to prevent the inertia of the recoil from disengaging the pawl,the spring should be strong enough to overcome the inertia of the blockF and the parts connected thereto, and also as an additional preventive,the notches on the arc are undercut, and the pawl is inclined slightlyupward, as is shown most clearly in Fig. 2. The sight is thus firmlyheld in position until the marksman desires to alter the elevation ofthe same.

The block F is placed within easy reach of the left-hand of themarksman, and he can thus operate the sight by the use of one hand.Moreover should the pawl-spring get broken or fail to operate, which isnot likely to hap- IOO IIO

pen, the marksman may readily hold the block F with his thumb Whiletiring, and thus insure the permanent elevation of the leaf D It Will beobvious that when the sight is not in use, the leaf will lie close alongthe barrel, and will not be likely to be accidentally injured. Moreoverthe adjustable parts project but little when in use, the pawl and itsattachments being close along the barrel, and the notched arc beingordinarily mainly inclosed within the stock. The drift should becompensated for by properly setting the front sight. Correction for windis considered a needless reinement for the practical purposes of themilitary or naval service.

It will be seen that in the sight herein described only one sight notch,one set of marks, and one origin are used; and thus the often needlessand generally bewildering array of figures and the complicated adjustmentsfof the sights most ordinarily in use are obviated.

It will be seen that the herein described sightis rigid, is notdisplaced by the recoil, has a small amount of projection either whenset or when not in use, is not delicate enough to be easily put out oforder, and is not difficult to repair.

It will also be evident that the herein den scribed sight with orwithout minor modifications is adapted for use in rapid fire guns andother ordnance.

These and the various other advantages of the herein described inventionwill readily suggest themselves to any one skilled 'in the use offirearms or cannon. l

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-- 1. In a sight, thecombination with a sight leaf pivoted approximately horizontally andconnected to the gun, and being provided with a sight notch and a brightstrip in the same vertical plane with the line of sight, of means forraising and lowering said pivoted leaf and of holding the same at anydesired elevation, substantially as described.

2. In a sight, the combination with a sight leaf pivoted approximatelyhorizontally and connected to the gun, the upper face of said leaf beingstriped longitudinally, a rear sight piece carried by said pivoted leaf,and means for raising and lowering said pivoted leaf and of holding thesame at any desired elevation, substantially as described.

3. A rear sight for guns consisting essentially of avertically movablesight piece pro` vided with a Y-shaped notch therein, the sides of saidnotch being bent outward at an angle toward their upper ends and beingannular in shape, thus forming an annular edge at or near the center ofthe sides of said notch, substantially as and for the purposesdescribed.

4. In a sight, the combination with a sight 6 5 leaf pivotedapproximately horizontally near its rear end and connected to the gun,and being provided with a sight notch near its forwardend anda brightstrip in the same vertical plane with the line of sight, of means forraising and lowering said pivoted leaf and of holding the same at anydesired elevation, substantially as described.

5. In a sight, the combination with a sight leaf. pivoted approximatelyhorizontallynear its rear end and connected to the gun, the upper faceof said leaf being striped longitudinally, a rear sight piece carried bysaid pivoted leaf near the front end thereof, and means .for raising andlowering said pivoted leaf and of holding the same at any desiredelevation, substantially as described.

6. In a sight, the combination with a sight leaf pivoted approximatelyhorizontally and connected to the gun, and being provided with a sightnotch of a graduated toothed arc rigidly connected to said leaf andmoving therewith, the teeth being shorter near the upper end of said arcand each succeeding tooth projecting beyond theone above, and a pawlengaging in said teeth and locking said are at any desired elevation,substantially as described.

7. In a sight, the combination with a sight leaf pivoted approximatelyhorizontally and connected to the gun, being provided with a sightnotch, of a graduated toothed arc rig.

' idly connected to said leaf and moving therewith, the teeth beingshorter near the upper end of said arc and each succeeding toothprojecting beyond theone above, and aspring operated pawl adapted tolock said arc at any desired elevation, substantially as described.

8. In a sight, the combination with a sight leaf pivoted approximatelyhorizontally and connected to the gun, and being provided with a sightnotch and a bright strip in the same vertical plane with the line ofsight, of a notched arc projecting from the said leaf and rigidlyconnected thereto, and a pawl holding said notched arc in any desiredposition, substantially as described.

9. In a sight, the combination with a sight leaf pivoted approximatelyhorizontally and connected to the gun, the upper face of said leaf beingstriped longitudinally, a rear sight piece carried by said pivoted leaf,a notched arc projecting from said leaf and rigidly connected thereto,and a spring operated pawl holding said are in any desired position,substantially as describe In testimony whereof I affix my signature inpresence of two witnesses.

ALBERT C. DIEFFENBAOH.

Witnesses:

JOHN C. WILSON, MAURICE J. SIoUssA.

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